1. Field of the Invention
The present invention relates to a fixing belt comprising an electroformed nickel endless belt body, used in a fixing section of an image-forming apparatus such a facsimile or a laser beam printer.
2. Description of the Related Art
As is well known in the art, a belt fixing system using an endless fixing belt (an endless belt or an endless film) in place of a fixing roller is employed in an image-forming apparatus in compliance with the demands for the miniaturization and the energy saving of the image-forming apparatus and for the increased speed in the printing and copying operation. The fixing belt is thin, and therefore can substantially directly heat the toner image on the recording medium by the heating from the inside the thin fixing belt only through the thin belt and fix the toner image. Accordingly, the fixing belt is advantageous in that it can shorten the waiting time after the turning on of the power source.
Use of an endless nickel belt prepared by electroforming as a belt body of the fixing belt is disclosed in, for example, Japanese Patent Disclosure (Kokai) No. 2002-148975. This patent document teaches that an endless nickel belt containing 0.01 to 0.1 mass % of carbon is prepared by the electroforming. Also, Japanese Patent Disclosure No. 2003-57981 discloses a belt fixing system using a halogen lamp as a heating source.
However, the conventional fixing belt having an electroformed nickel belt body fails to exhibit a sufficient resistance to thermal fatigue at high temperatures, and is poor in its durability. More specifically, in the case of the belt fixing system, the rear surface of the belt body of the fixing belt is deteriorated by heat so as to generate cracks, leading to the problem that the belt body is broken.